Radioreception



Oct. 4, 1932. w. AULL, JR 1,881,395

RADIORECEPTION Filed Dec. so. 1927 4 Sheets-Sheet 1 VENTOR ATTORNEY Oct. 4, 1932. w, AU JR' 1,881,395

RADIORE CEPTION Filed Dec. 50, 1927 4 Sheets-Sheet 2 IN VENTOR Wilson wZZ J7:

% ATTORNEY 0st 4, 1932. w. AULL, JR 1,381,395

RADIORECEPTION Filed Dec. 50. 1927 4 Sheets-Sheet s INVENTOR Wilson ZZJi? V 'ITORNEY W. AU LL, JR

RADIORECEPTION Get. 4, 1932.

Filed Dec. 30, 1927 4 Sheets-She'r. 4

HOHNHHH INVENTOR Whom flwZZJ/ Patented Oct. 4, 1932 ren STATES WILSON AULL, 13., OF ASTOR-IA, NEW YORK RADIOREGEPTION Application filed December 39, 1927. Serial No. 243,661.

One object of my invention is to produce a radio receiver, the response frequency and output volume of which may be controlled from a distance from a readily portable control box.

Another object is to produce a radio receiver in which the larger units having a multiplicity of vacuum tubes may be placed in the attic, a closet, or other appropriate and outofthe-way place, and need not be disturbed except for repair or replacement.

Another object is to produce a radio receiver having the foregoing propertles 1n which no oscillating vacuum tubes are employed.

In its broad aspect the invention contemlates the reception and substantially uniform amplification of all signals of various frequencies within some predesigned band, 2 the selection and radio amplification of the desired signal by a control unit and the retransmission of the amplified signal at 1ts original frequency to an aperiodic receiver where it is demodulated and further amplified at audio frequencies.

Referring to the drawings, Fig. 1 shows a receiver in which the loud speaker and detector-amplifier system are particularly intended to be operated from the house ourrent. A portable control box is used in conjunction with a broadcast frequency bandpass amplifier, which latter may be located in some out-of-the-Way place.

Fig. 2 shows a receiver in which the bandpass amplifier and receiver proper may both be concealed, a loud speaker used with an extension cord, or built-in wiring, and a control box which may readily be moved from room to room.

Fig. 3 shows a schematic wiring diagram of a typical band-pass amplifier embodying a balancing system, an input system, and an output system, operated from an alternating current house line.

Fig. 4: shows a schematic wiring diagram of a form of control box, using three-element vacuum tubes.

Fig. 5 shows the wiring for another form of control box using a shielded grid type of so tube having four elements.

Fig. 6 shows a schematic wiring diagram of one form of what might be called the final receiver embodying one aperiodic radio frequency stage, a detector and two audio frequency stages, all arranged for operation from an alternating current house line.

In Fig. 1, 10 is a band-pass amplifier which amplifies all received frequencies within the desired band substantially uniformly. This amplifier may contain the apparatus indicated in Fig. 3, or may be similar to the bandpass amplifiers described in Patents 1,746,688, 1,746,689 and 1,794,935. The input system of this amplifier may consist of the antenna 11 and the ground 12 and its output system, the antenna 13 and the counterpoise 14. A cord and plug 15 is shown for connection for power operation.

The control box 16 may be equipped with the input antenna 17 and the output antenna 18. The manual frequency control is indicated at 19 and the scale or dial at 20. This control box contains a selective radiofrequency amplifier of either the form indicated in Figs. 4 or 5, or other suitable apparatus.

The receiver 21 with its input device 22 is in this instance power-operated having a cord and plug attachment 23, and will conv tain a detector and audio-frequency amplifier such as schematically indicated in Fig. 6, or other apparatus suitable for the purpose in view and a loud speaker 29.

In Fig. 2 the band-pass amplifier 25 which may be similar to 10 in Fig. 1 is equipped with an input system consisting preferably of the antenna 11 and the ground 12 and an output system consisting of the antenna 13 and the counterpoise 14. The control box 26 may be similar to the control box 16 in Fig. 1. The final receiver 27 having an input. device 28 and a loud speaker 29 may be similar electrically to the receiver 21, but it is so designed that the loud speaker is separate and the receiver may be concealed 95 along with the band-pass amplifier 25, an extension wiring of some sort being provided for the loud speaker.

Fig. 3 shows a typical power operated radio frequency band-pass amplifier, such as 1 may be employed with my invention. The amplifier proper 10 is indicated as shielded by the partitioned metallic case 36. It is provided with an input system consisting of the antenna 11, the ground 12 and an output system consisting of the antenna 13 and the counterpoise 14. The condensers 41 and 42 are provided to keep the high voltage direct current anode supply from the antenna system as a precaution against accidental shocks. Four stages of untuned radio frequency amplification are shown employing a balancing system to prevent oscillation. The last stage employs a power tube 43, the output of which is fed into the output system 13 and 14 by the voltage drop across the inductive reactance 44. The power supply system is shown at 50. An attachment cord and plug is shown at 51. The cathode heating transformer 52 is provided with a primary winding 53 and two secondary windings 54 and 55 each provided with the usual center tap. The secondary 54 supplies heating current to the cathodes of the tubes of the first three-stages. The secondary 55 supplies heating current to the cathode of the power tube 43. The transformer 56 having the primary winding 57 is provided also with two secondary windings, both having the usual mid-tap. The secondary 58 supplies heating current for the cathode of the full wave rectifier tube 59, while the secondary 60 provides the anode voltage for this rectifier and after filtration the anode voltage for the amplifier 10. The inductances 60 and 61 and the capacities 62, 63 and 64 form a filter. It will be seen that the full voltage of the anode supply system is supplied to the anode of the tube 43 while due to the resistors 65 and 66 a reduced voltage is supplied to the anodes of the preceding stages. The resistors 67 and 68 are for the purpose of placinga negative potential on the grids of the various amplifier tubes.

Fig. 4 shows schematically the interior apparatus of one form of control box. The input consists of the coil antenna 17 tuned by the variable condenser 71. Three electrode vacuum tubes 72 and 7 3 and 74 are employed. The loop antenna 18 is shown in the output circuit of the tube 74. The tubes may be coupled by the broad band transformers 76 and 77 and the amplifier may have its total gain controlled by any convenient means such as the variable resistance shown at R.

densers may preferably be adjusted simultaneously by one manual control, as indi cated by 86. The resistors 87 and 88 are inserted to secure proper negative bias on the control grids 89 and 90. The total gain of this amplifier may be controlled by means such as variation of the resistor 88, as indicated by the arrow thereon.

Fig. 6 shows an arrangement for a power operated final receiver. One stage of aperiodic radio frequency amplification is shown at having an untuned coil antenna 22 as an input device. This stage is coupled by a band frequency coupling mesh consisting of the inductors 97 and 98 and the condensers 99 and 100 to the detector 101 which, as will be seen, is ofthe indirectly-heated cathode type. The two following stages of audio frequency amplification 102 and 103 are quite conventional and therefore not described in detail. An output transformer 104 may be provided and a loud speaking telephone is indicated 7 at 29. indicates a cord and plug for connectionto the house alternating current lines. The transformer 111 is provided with a primary 112 and has three secondaries 113, 114 and 115. The secondary 113 supplies heating current for the vacuum tube of the final or output audio frequency stage 103. The resistor 116 with its by-pass condenser 117 supplies a negative grid potential for the output stage. The secondary 114 provides cathode heating current for, the aperiodic radio frequency'stage95 and the first audio frequency stage 102. The central point of connection for the cathodes of the tubes of these two stages is provided for by the resistor 118 and the negative grid potential by the resistor 119. The secondary supplies cathode heating current for the detector tube 101. -The transformer is provided with a primary winding 126 and switch selected taps as 127, to compensate for variations in line voltage. This transformer is provided with two secondaries 128 and 129 each having the usual mid-point connection. The output of the secondary128 is employed to heat the cathode of the full wave rectifier 130. The output of the secondary 129 is employed as a source of anode voltage for the vacuum tubes employed in the receiver proper.

The inductors 131 and 132 and the condensers 133, 1.34 and 135 form the usual filter system to remove the pulsations from the output of the full wave rectifier 130. It will be seen that the full voltage of the anode supply source is employed in the output stage 103 and that owing to the arrangement of the resistors 137, 138 and 139 a somewhat lower voltage is employed in the aperiodic radio frequency stage 95 and in the first audio frequency stage 102, and a still lower voltage is employed in the detector 101.

The condensers 140 and 141 are employed as by-pass condensers merely to prevent interstage anode circuit coupling. The grounded shield indicated at 142 may be employed to separate the power source from the receiver proper.

In operation (referring to Fig. 1) the antenna system 11 and 12 picks up all signals within the distance range and frequency range of the system. These signals are substantially uniformly amplified without demodulation or change of frequency by the band-pass amplifier and retransmitted, greatly strengthened, by the output system 13 and 14 of said amplifier.

By means of the tuning or frequency control 19 of the control station 16, the desired amplified signal may be chosen and reamplified. This signal is then retransmitted by means of the output device 18 to the aperiodic pick-up 22 of the receiver 21 where it may be further amplified, demodulated, amplified at audio frequencies and converted from electrical energy to sound energy by means of a loud speaking telephone.

It is, of course, necessary either by arranging the plane of polarization of the various antennas, or by proper phasing between the inputs and outputs of the various units to prevent overall regeneration or degeneration, and it is also important that the directional reception pattern of input device 22 should be such that substantially no energy is directly received from the output system 13 and 14 of the band pass amplifier 10.

It should be understood that I do not wish to limit myself to the particular types or arrangements of selectors and radiators shown in the drawings, but that other suitable comx binations of Well known forms, such as, coils,

loops, electrostatic and open antenna may be employed for certain purposes.

The volume or amount of energy radiated may be controlled by any of the well known means heretofore used in ordinary radio frequency amplifiers as for instance by a variable resistance R in Fig. 4 or avariable filament resistance 88 in Fig. 5.

The broad band filter amplifier may be turned on and off by a switch 49 which may be operated manually or by relays as in application No. 198,470, filed June 13, 1927, or 220,137, filed September 17, 1927, or Patent 1,795,269. lhe power supply for the repro- 5 ducing receiver 21 may be similarly controlled. I reserve the right to claim the details of such remote control systems in other applications.

I claim:

1. A system of household broadcast reception which comprises means for receiving and simultaneously amplifying with substantial uniformity various frequencies within a predetermined band of frequencies, separately portable means for selecting signals of the desired frequency and amplifying the same to a controlled extent, means for transmitting the amplified and selected signal at its original frequency and an aperiodic receiver including means for picking up and demoducomprises means for receiving and amplifying various frequencies within a predetermined band of frequencles, sald means comprising an untuned amplifier embodying means for balancing-out valve coupling, separately portable means for selecting signals of the desired frequency and amplifying the same to a controlled extent, means for transmitting the amplified and selected signal at its original frequency and an aperiodic receiver including means for picking up and demodulating the transmitted signal and further amplifying the same at audio frequencies, and means for reproducing the further amplified signals.

3. A household receiving set comprising separate and distinct radio frequency amplifying, control and reproducing units, said amplifying unit including pick-up means for broadcast signals, means for amplifying all broadcast signals within a broad band of frequencies and means for radiating the amplified signals, said control unit including pickup selecting and controlling means for receiving the amplified signals and re-radiating means for changing the plane of polarization of the carrier wave of the selected frequency, means for controlling the field strength of the re-radiated energy, said reproducing unit including pick-up means arranged in a plane to receive the re-radiated selected signal frequency, detecting means and means for converting the detected signal into sound.

4. A household broadcast receiver comprising means for collecting and amplifying at radio frequencies all signals within a broad band of frequencies, a portable control unit including sole means for selecting and amplifying the desired signal frequency, means for radiating the selected and amplified signal in a plane materially different from the plane of the broadcast waves, and a separately portable reproducing unit having pick-up means ready selection of a narrow band of frequencies from Within the broad band, means for amplifying said narrow band to a controlled degree and means for radiating at the same L7 frequency the amplified narrow band of frequencies. at a level sufficiently great to satisfactorily actuate a detecting and amplifying unit, and such unit having pick-up means adj usted to be relatively insensitive to any electro-magnetio field in its vicinity, other than the amplified field radiated by the portable control means, and having means for demodulating the preselected and amplified signals, and means 'for amplifying at audio frequencies said demodulated signals.

WILSON AULL, JR. 

